1. Field of the Invention
This invention relates to improvements in a clutch release apparatus having a self-aligning mechanism.
2. Description of the Prior Art
The clutch release apparatus is interposed between a diaphragm spring and a fork member in the clutch mechanism of a vehicle, and comprises a clutch release bearing having a portion brought into contact with the diaphragm spring, and bearing holding means slidably disposed on a fixed guide for holding the clutch release bearing and receiving a drive force from the fork member. An axial drive force applied to the fork member is transmitted from the clutch release bearing to the diaphragm spring through the bearing holding means to release the clutch.
It is necessary that the clutch release bearing be made alignable to compensate for eccentricity (deviation of the axis) or inclination caused between the central axis thereof and the central axis of the diaphragm spring during assembly. Various contrivances have heretofore been made in order to hold the clutch release bearing in alignment relative to the bearing holding means, and an example thereof is shown in FIG. 1 of the accompanying drawings (Japanese Laid-open Utility Model Application No. 137726/1980).
In FIG. 1, a fork receiving member 4 is fitted to a sleeve 2 slidably disposed on a fixed guide, not shown, and a spherical free wheel 8 having a spherical surface 6 is mounted in a corner portion defined by the sleeve 2 and the fork receiving member 4. A clutch release bearing 10 has a bearing portion 14 for acting upon a diaphragm spring 26. Bearing portion 14 is made integral with an inner race 12 and is held by a support cover 18 fitted to an outer race 16. The inwardly facing flange 20 of the support cover 18 extends between the bearing 10 and the spherical free wheel 8 and is contact with the spherical surface 6 of the free wheel 8 along a conical surface 22 thereof. A planar surface 27 of the spherical free wheel 8 is adapted to be guided in a direction perpendicular to the axis by the flat surface of a friction plate 28 secured to the surface of the fork receiving member 4 which is opposed to the free wheel 8. The support cover 18 of the bearing 10 is such that the spherical surface 6 and the conical surface 22, and the planar surface 27 and the surface of the friction plate 28 are positively brought into contact with each other by resilient means 24 secured to the sleeve 2.
In operation of the above-described device, when there is eccentricity or inclination of the central axis between the bearing 10 and the diaphragm spring 26, the bearing 10 rocks due to centripetal force. The conical surface 22 and the planar surface 27 are guided as the bearing rocks by the spherical surface 6 and the friction plate 28, respectively, whereby the eccentricity or inclination is adjusted.
However, in such apparatus wherein the free wheel 8 is adapted to be moved in a plane perpendicular to the axis relative to the fork receiving member 4 and wherein the bearing 10 is adapted to rock while being guided by the spherical surface 6 of the free wheel 8, the alignment stability for vibration or shock is generally inadequate.